The present invention relates to lasers, and, in particular, relates to gaseous lasers, and, in greater particularity, relates to cw photolytic lasers.
A prior cw iodine laser operated at 1.315 microns and had an unlimited operating time. This utilized a high pressure, water cooled, d.c. Hg arc lamp for the ultraviolet (UV) photolysis of the alkyl-iodine laser fuel (specifically C3F7I) and either used longitudinal or transverse flow in the gain cell. Both the ground state iodine atoms and the photolytic quenching by-product I.sub.2 were removed which is necessary to sustain cw operation. The unlimited operating time was achieved by using a passive closed cycle C.sub.3 F.sub.7 I gaseous supply system which removed the I.sub.2 from the C.sub.3 F.sub.7 I laser fuel via a condensation/evaporation process and simultaneously created the required flow velocity. Better performance was achieved using transverse flow since a more constant flow velocity occurred across the lasing region. These excellent results, however, occurred at low output powers of a few milliwatts. Such low powers made this cw photolytic iodine laser useful only as a gain probe of iodine media like Chemical Oxygen Iodine Lasers (COIL) or pulsed photolytic iodine devices.